Apparatus for forming a rolled edge on containers made of sheet material



y 9, 1967 R. G E. DURAT 3,318,203

APPARATUSFOR FORMING A ROLLED EDGE ON CONTAINERS MADE OF SHEET MATERIALFiled Aug. 10, 1965 mm k United States Patent 3,318,203 APPARATUS FORFORMING A ROLLED EDGE ON CONTAINERS MADE OF SHEET MATERIAL RobertGeorges Eugene Durat, J ouet-sur-lAubois, Cher, France Filed Aug. 10,1965, Ser. No. 478,688 Claims priority, application France, Apr. 27,1965, 14,779, Patent 87,743 7 Claims. (Cl. 93-36.5)

Devices are already known for forming rolled edges on containers made ofsheet material, such devices comprising, on the one hand, a rolling toolconsisting of a central part with a hollow quarter-torus shaped externalthroat thereon and of jaws which are mounted under slight friction onthe support of said part, whereby to slide radially behind the latter,and which have a hollow half-torus shaped groove on their inner surfaceswhich forms a rolling die jointly with said throat, and, on the otherhand, means for moving said tool axially toward the contanier mounted ona fixed coaxial support, whereby to cause its edge to be rolled down insaid die, means for opening said jaws on completion of the rolled edgeand means for reclosing them on recession of said tool from thecontainer with its rolled edge.

Such a device is described in US. Patent application Ser. No. 428,324,filed by the applicant on Jan. 27, 1965.

The device according to the above-cited patent application will notpermit the use of sheet material of any kind or thickness. Thus, whencardboard of a thickness exceeding a certain value is used for example,breaks occur along the rolled edge.

The present invention has for its object to widen the range of sheetmaterial usable for forming rolled edges, and accordingly relates to anapparatus for forming rolled edges on sheet-material containers of thetype hereinbefore specified, wherein said rolling tool is rotatableabout its longitudinal axis relatively to the container, which containeris coaxial therewith and mounted on a fixed support. In a preferred formof embodiment, the tool-carrier hereinabove specified is mounted in ahearing with a fixed external cage and is continuously rotated by anyconvenient means.

In accordance with the present invention, a rolling die as hereinabovedisclosed is formed with splines with rounded corners and is preferablymade of steel. The expansion which the cardboard undergoes when therolled edge is being formed is no longer produced by pressure, as such,but by a periodic deformation of the fibers as they transit in rotationover the toroidal protrusions which said splines constitute.

t Preferably, the jaws forming part of the rolling die are locked whenoperating in the closed position, by means of a keeper-ring locatedbetween the hollow tool body and the slides described in the above-citedpatent application, in two facing circular grooves formed in thesemembers. Such locking is necessary in order to render the jaws immovableand prevent them from opening in response to the centrifugal forcegenerated by the rotation of the apparatus.

Likewise in accordance with the invention, tool movement is controlledby a cam which is so contoured as to permit rapid approach of the tooltoward the container, slow formation of the rolled edge thereon, rapidopening of the jaws and rapid return motion of the assembly.

The description which follows with reference to the acompanyingnon-limitative exemplary drawings will give a clear understanding of howthe present invention can be carried into practice.

In the drawings:

FIG. 1 shows in longitudinal section the apparatus for forming rollededges according to the present invention;

FIG. 2 is a front elevation view on an enlarged scale of the centralpart which, jointly with the jaws, forms the rolling die of FIG. 1;

FIG. 3 is a sectional view taken on the line IIIIII of FIG. 2; and

FIG. 4 is a fragmental the line IV-IV of FIG. 3.

Like in the above-cited patent application, the purpose of the apparatusshown in the accompanying drawings is to form a rolled edge on theopening 1 of a frustoconical container 2 open over its smaller base.This container is mounted in a fixed support 3 and centered thereon by ahollow frusto-conical part 4. The larger base of the container bears ona surface 5 consisting, say, of the thrust face of a tool used tocomplete the fitting of the container bottom.

The means for forming the rolled edge include a hollow tool-carrier 6coaxial with the part 4 and rotatably mounted in a bearing 61 the outercage of which is rigidly united with a fixed support 62 through themedium of a ring 63. At its end remote from the container 2, thetoolcarrier 6 is equipped with a pulley 64 which is continuously rotatedby a V-belt 65 driven by any convenient means. A key 66 rigid with thetool-carrier 6 is slidable in a longitudinal groove formed in the hollowtool body 12 and serves to transmit the rotation to the latter.

Like in said patent application, a hollow tool body 12 is slidablymounted in the hollow tool-carrier 6, and a shaft 15 is slidably mountedin this tool-body 12. Likewise to be found are the slides 17, the jaws28 and the frusto-conical part 32, except that the latter, which isprefenably made of treated steel, has a hollow half-torus shaped throat36 formed thereon, while the grooves 37 of jaws 38 which extend it arein this case shaped as a hollow quarter-torus. Further, thefrusto-conical portion of the part 32, the throat 36 and the grooves 37are formed with radial splines 67, all the corners of which are roundedas is clearly shown in FIGS. 2 and 4. In addition, the rotating motionis transmitted to the rolling die 32, 36- by means of two pegs 69rigidly connected to the tool body 12, parallel to the axis thereof.These pegs extend through oblong openings 70 formed in two of thediametrically opposed slides 17 and penetrate into blind holes 71 formedin the frusto-conical part 32.

In order to prevent the jaws 28 from loosening responsively tocentrifugal force when they are operative in the closed position, akeeper-ring 68 made of spring wire is fitted between the hollow toolbody 12 and the slides 17, in facing circular grooves formed in the toolbody and the slides respectively.

In order to achieve the axial displacement of the rolling tool requiredto move the rolling die toward and away from the container 2, a bearing72 gripped between two nuts 44 and 45 is mounted on the threaded end 43of the shaft 15. The outer cage of this hearing is rigid with a part 73to which is pivotally connected a link. 74 the other end of which is inturn pivotally connected to a beamlever 75. The latter is fixedlyfulcrumed about a point 76 and its other arm bears a follower 77 whichis urged against a cam 78 by a spring 79 connected across the beam-leverand the fixed support 62.

The distance of the contour of the cam 78 from its axis remains constantover a quarter-circumference 78a, then increases rapidly oversubstantially 45 along 78b, after which it continues to increase veryslowly over a half-circumference 78c and finally decreases very rapidlyover approximately 45 along 78a, to revert to its initial value. Thedirection of rotation of the cam is such that the follower 77successively rides over the sectors 78a, 78b, 78c and 78d.

sectional view taken through The second sector 78b corresponds to arapid approach of the rolling tool toward the container 2; the transitof the roller over the next sector 7 80 produces a slow travel of thetool in the same direction, during which phase the rolled edge isformed; the sector 78d corresponds to a rapid return motion of theassembly to its initial position following rapid opening of the jaws 28;the tool then remains in this position while the follower 77 rides overthe cam sector 73a, during which time a fresh container can be movedinto position for processing.

Except for these differences, the apparatus hereinbefore describedoperates exactly in the same manner as the apparatus which is describedin the above-cited U.S. patent application Ser. No. 428,324.

What I claim is:

1. In an apparatus for forming rolled edges on a container of revolutionmade of sheet material, mounted on a fixed support comprising, incombination, a central part which is coaxial with the container mountedin its fixed support and which has formed thereon rearwardly of itsperiphery a circular hollow half-torus shaped throat at a distance fromthe container axis equal to the distanc from said axis of the containeredge to be rolled down, a movable hollow supporting member coaxial withand spaced from the rear of said part, a plurality of jaws mounted onsaid supporting member, radially movable in said space in contact withsaid central part and said supporting member and projecting radiallyforwardly from the periphery of said central part, said jaws havingformed thereon facing said part on their forwardly projecting portions acircular hollow quarter-torus shaped groove which, when said jaws are intheir retracted positions, jointly form with said throat a rolling diethe section of which is a hollow three-quarter-torus opening out in thedirection of the container, means for applying said jaws against saidflange under slight pressure, means for applying said central partagainst said jaws under slight pressure, means for axially displacingsaid supporting member toward the container whereby to roll back theedge thereof externally in said die and move said supporting member awayfrom the container after formation of the rolled'edge, means forradially displacing said jaws between said supporting member and saidcentral part on completion of the rolled edge whereby to open said die,means for reclosing said jaws on recession of said supporting memberfrom the container with its rolled edge, and means for controlling saiddisplacing means, the improvement comprising, in combination, means forrotatably mounting said rolling die about the axis of the container andmeans for rotating said rolling die.

2. An apparatus as claimed in claim 1, wherein said rolling die hasradial splines with rounded corners formed thereon.

3. An apparatus as claimed in claim 2, wherein said central part andsaid jaws are made of treated steel.

4. An apparatus as claimed in claim 1, comprising a hollow tool bodyformed with a flanged end and a longitudinal groove, slides mounted onsaid flange and having openings therein, said central part and said jawsbeing mounted on said slides, pegs rigid with said flange, extendingthrough said openings and penetrating into said central part, a hollowtool-carrier surrounding said tool body, a key rigid with the interiorof said tool-carrier and penetrating into said groove, a fixed bearingin which said hollow tool-carrier is mounted, a pulley rigid with saidtoolcarrier and means for rotating said pulley.

5. An apparatus as claimed in claim 4, wherein said slide has a firstcircular groove formed thereon and said flange has a second circulargroove formed thereon facing said first groove, a spring wire beingaccommodated in said grooves.

6. An apparatus according to claim 1, wherein said means for controllingsaid displacing means comprise a shaft slidably mounted in said hollowsupporting member and of which the end remote from said container isthreaded, an annular connecting member, a bearing mounted in saidannular member and engaging over the threaded end of said shaft, twonuts on said threaded end on either side of said bearing, a linkpivotally connected to said annular member, a fixedly fulcrumed leverpivotally connected to said link, a cam-follower on said lever, a camwith which said follower is in pressure contact, and means for rotatingsaid cam about its axis.

7. An apparatus as claimed in claim 6, wherein the distance between thecontour and the axis of said cam is constant over substantially rapidlyincreases over substantially 45, slowly decreases over substantially andrapidly decreases over substantially 45.

References Cited by the Examiner UNITED STATES PATENTS 2,473,836 6/1949Wixon et al. 93-36.5 2,778,287 1/1957 Moore 93--36.5 2,819,658 l/1958Scott et al. 93-365 WILLIAM W. DYER, 111., Primary Examiner.

JAMES M. MEISTER, Examiner.

1. IN AN APPARATUS FOR FORMING ROLLED EDGES ON A CONTAINER OF REVOLUTIONMADE OF SHEET MATERIAL, MOUNTED ON A FIXED SUPPORT COMPRISING, INCOMBINATION, A CENTRAL PART WHICH IS COAXIAL WITH THE CONTAINER MOUNTEDIN ITS FIXED SUPPORT AND WHICH HAS FORMED THEREON REARWARDLY OF ITSPERIPHERY A CIRCULAR HOLLOW HALF-TORUS SHAPED THROAT AT A DISTANCE FROMTHE CONTAINER AXIS EQUAL TO THE DISTANCE FROM SAID AXIS OF THE CONTAINEREDGE TO BE ROLLED DOWN, A MOVABLE HOLLOW SUPPORTING MEMBER COAXIAL WITHAND SPACED FROM THE REAR OF SAID PART, A PLURALITY OF JAWS MOUNTED ONSAID SUPPORTING MEMBER, RADIALLY MOVABLE IN SAID SPACE IN CONTACT WITHSAID CENTRAL PART AND SAID SUPPORTING MEMBER AND PROJECTING RADIALLYFORWARDLY FROM THE PERIPHERY OF SAID CENTRAL PART, SAID JAWS HAVINGFORMED THEREON FACING SAID PART ON THEIR FORWARDLY PROJECTING PORTIONS ACIRCULAR HOLLOW QUARTER-TORUS SHAPED GROOVE WHICH, WHEN SAID JAWS ARE INTHEIR RETRACTED POSITIONS, JOINTLY FORM WITH SAID THROAT A ROLLING DIETHE SECTION OF WHICH IS A HOLLOW THREE-QUARTER-TORUS OPENING OUT IN THEDIRECTION OF THE CONTAINER, MEANS FOR APPLYING SAID JAWS AGAINST SAIDFLANGE UNDER SLIGHT PRESSURE, MEANS FOR APPLYING SAID CENTRAL PARTAGAINST SAID JAWS UNDER SLIGHT PRESSURE, MEANS FOR AXIALLY DISPLACINGSAID SUPPORTING MEMBER TOWARD THE CONTAINER WHEREBY TO ROLL BACK THEEDGE THEREOF EXTERNALLY IN SAID DIE AND MOVE SAID SUPPORTING MEMBER AWAYFROM THE CONTAINER AFTER FORMATION OF THE ROLLED EDGE, MEANS FORRADIALLY DISPLACING SAID JAWS BETWEEN SAID SUPPORTING MEMBER AND SAIDCENTRAL PART ON COMPLETION OF THE ROLLED EDGE WHEREBY TO OPEN SAID DIE,MEANS FOR RECLOSING SAID JAWS ON RECESSION OF SAID SUPPORTING MEMBERFROM THE CONTAINER WITH ITS ROLLED EDGE, AND MEANS FOR CONTROLLING SAIDDISPLACING MEANS, THE IMPROVEMENT COMPRISING, IN COMBINATION, MEANS FORROTATABLY MOUNTING SAID ROLLING DIE ABOUT THE AXIS OF THE CONTAINER ANDMEANS FOR ROTATING SAID ROLLING DIE.